Multiple glazed unit



June 3, 1941.

O. D. ENGLEHART MULTIPLE GLAZED UNIT Filed June 23, 1939 l I I I I I I I I I I I .I

I I I I I I I I o I I I 1 I I I I I INVENTOR OJCfiE 0. Elva-1.. EHn/e-r AT TORNEY.

Patented June 3, 1941 MULTIPLE GLAZED UNIT Oscar D. Englehart, Brackenrldge, la., assignor to Pittsburgh Plate Glass Company, County, Pa., a corporation of Pennsyl Allegheny Vania.

Application June 23, 1939, Serial N0. 280,730

2 Claims.

The present invention relates to glazed structures and more particularly to multiple glazed units wherein spaced glass sheets are secured in a frame.

One object of the invention is the provision of an improved sealing means effectively reducing the entrance of moisture and foreign matter into the air space between the glass sheets while, at the same time, reducing the pressure ordinarily exerted upon the edges of the glass sheets.

Other objects and advantages of my invention will become more apparent from the following detailed description of a particular embodiment thereof.

Multiple glazing has recently developed into considerable commercial importance and it is the subject of much research. Although there are presently available ,insulating units of proven effectiveness certain disadvantages remain unremedied. One such problem is the difficulty of obtaining a satisfactory seal between the sheets of glass in order that communication of the air space therebetween with the atmosphere may be prevented. Many types of seals have been suggested and tested with varying degrees of success.

Generally, it is necessary that the sealing me dium be partially resilient in order that the socalled breathing action, occurring under differences in pressure, temperature, etc. and flexing the glass sheets, will not rupture the seal. Rubber, synthetic resins and similar materials have been found most suitable as the sealing media. Strips of these materials are inserted between Figure 2 is a fragmentary vertical sectional view thereof.

In the drawing, a unit I comprises a frame 2 of metal, wood or other suitable material prothe glass sheets and placed under compression by a gripping action of the surrounding frame. These units can be assembled only at the factory and when placed in service, if they are damaged in any way, must be returned to the factory for repairs. The considerable force which must be exerted by the frame elements to obtain suitable compression is concentrated at the edges of the glass sheets and there have been observed numerous cases of breakage for this reason.

Briefly stated, the present invention contemplates the provision of a multiple glazedunit incorporating resilient sealing strips which are compressed centrally and expanded against the glass sheets, the compression strip also reducing the diffusion path for moisture vapor through the sealing medium- One embodiment of my invention is shown in the accompanying drawing, wherein:

Figure 1 is a front elevational view of a multiple glazed unit constructed in accordance with the provisions of the invention; and

vided with rabbeted grooves 3 in which a plurality of sheets 4 of glass protected by cushioning members 5 substantially of U shape in cross section are seated. Retaining strips 1 fastened to the frame by means of screws 8 or other fas: tening devices secure the sheets of glass within the frame.

Strips III, of rubber, synthetic resin or other resilient material lie between the sheets of glass, resting upon and extending continuously around the inner periphery of the frame 2. Strips ll of metal or similar rigid material are superposed upon the strips Ill and are engaged by screws l2 at spaced intervals therealong, through the operation of which the strips II are drawn toward the frame 2. This action causes the strips iii to be compressed and forced outwardly against the sheets of glass. It is preferred to form the strips H with a convex surface on that face contacting the strips ill in order that the major part of the compression is exerted centrally of the strips III. In this connection, also, the inner periphery of the frame may also have a convex surface.

The disclosed sealing means is applicable to substantially all types of multiple glazed units. The inclusion of desiccators or ventilators in the units will not detract from the efficacy of the seal in the first case or a reduction in edge stresses in the latter. Where the unit is to be completely sealed, it is possible, through the porosity of the sealing medium, that there will be a slight diffusion of water vapor into the enclosed air space. The diffusion path is reduced to a minimum in iny device, since the sealing strip is substantialy covered by a rigid nonporous backing member. -Another advantage of my invention resides in the fact that the sealing medium automatically compensates for variations in thickness of the glass sheets.

It will at once be obvious that variation of the shape or arrangement of the component elements are possible without departing from the spirit of the invention or the scope of the appended claims.

What I claim is:

1. In combination in a multiple glazed unit, a frame, a plurality of glass sheets secured within the frame, rubber strips lying between the glass sheets adjacent the peripheries thereof, strips of rigid material superposed upon the rubber strips,

and means drawing the rigid strips down upon the rubber strips compressing the rubber centrally and forcing it outwardly against the glass sheets.

2. In combination in a multiple glazed unit. a irame, a plurality of glass sheets releasably secured within the frame, strips of resilient material lying between the glass sheets upon the frame, strips of rigid material superposed upon the strips of resilient material, and screws projecting through the frame and resilient material into the strips 01 rigid material drawing the rigid strips toward the frame to compress the resilient material centrally and force it outwardly against the glass sheets.

' OSCAR D. ENGLEHART. 

